Results from the first large-scale, prospective study of prenatal methamphetamine use show that newborns exposed to the drug are more than three times as likely to be born underweight. Appearing in Pediatrics, the findings mirror those from studies of prenatal cocaine use, says Barry Lester, a professor and researcher at Brown Medical School and Women & Infants Hospital.

PROVIDENCE, R.I. — Newborns whose mothers used
methamphetamine during pregnancy are 3.5 times more likely to be born
underweight compared to newborns whose mothers didn’t use the drug,
according to a research study led Brown Medical School Professor Barry
Lester.

The study, published in Pediatrics, is the first
large-scale investigation of the prenatal effects of methamphetamine, a popular
and highly addictive stimulant. It is also the first prospective study: these
infants will be followed over time.

Results show that newborns exposed to the drug were not born too
soon – they were born too small. Methamphetamine appears to restrict the
nutrient-rich flow of blood into the placenta, increasing the risk that the
newborn will be “small for gestational age” – born full-term
but below the 10th percentile for weight. Growth-restricted newborns in the
study weighed less than 5 pounds.

The long-term effects of growth restriction can be serious.
These children are more likely to develop type 2 diabetes and metabolic
syndrome, a collection of heart attack risk factors such as high blood pressure
and obesity.

“We’re also very concerned about the developmental
implications,” said Lester, a professor of pediatrics and psychiatry and
human behavior and director of the Brown Center for the Study of Children at
Risk, which was established with Women & Infants Hospital in Providence.
“Children who are born underweight tend to have behavior problems, such as
hyperactivity or short attention span, as well as learning
difficulties.”

Researchers enrolled 1,618 patients in the study from four
medical centers, located in Tulsa, Okla., Des Moines, Iowa, Los Angeles and
Honolulu. Women were asked if they had used methamphetamine, but researchers
also checked for evidence. Meconium, a newborn’s first few stools and also
a buildup of material gained during pregnancy, was scraped from diapers and
chemically screened for the presence of the drug.

Results showed that 1,534 newborns were unexposed to
methamphetamine in utero. Another 84 newborns were exposed – and were more
than 3 times as likely to be born too small. Researchers arrived at that figure
even after adjusting for other factors that may contribute to growth
restriction, such as socioeconomic status and other substance use, including
tobacco and alcohol.

Lester has studied the effects of drug use on infants and
children for more than 20 years. He oversees the Maternal Lifestyle Study, the
nation’s largest prospective study of cocaine-exposed children. About
1,400 newborns were enrolled in Providence, Detroit, Memphis and Miami. Those
children are now turning 13, and researchers continue to study how prenatal
cocaine exposure, by itself and in combination with other drug and environmental
factors, affects their cognitive, psychological, behavioral and emotional
outcomes as well as their school performance.

Lester said initial results from the methamphetamine study,
called the Infant Developmental Environment and Lifestyle Study (IDEAL), mirror
early results from the Maternal Lifestyle Study. In that study, researchers also
found that cocaine-exposed newborns were more likely to be born small for
gestational age.

“Both of these drugs are central nervous stimulants, and
it appears that both drugs have similar effects on the developing fetus,”
he said. “But I hope that the ‘crack baby’ hysteria does not
get repeated. While these children may have some serious health and
developmental challenges, there is no automatic need to label them as damaged
and remove them from their biological mothers. There are alternatives for the
mother and the baby that can keep families together, such as the specialized
drug court we established here in Providence that is based on treatment, rather
than punishment.”

The research team will follow infants in IDEAL until the infants
are 3 years old. With additional funding, the team will follow them for even
longer.

Lynne Smith, M.D., a researcher with the Los Angeles Biomedical
Institute at Harbor-UCLA Medical Center and the David Geffen School of Medicine
at UCLA, is the lead author of the Pediatrics article. Linda LaGasse,
Sheri Della Grotta and Jing Liu of the Brown Center for the Study of Children at
Risk are also authors. Others include Chris Derauf, M.D., and William Haning,
M.D., University of Hawaii; Penny Grant, M.D., University of Oklahoma; Amelia
Arria, University of Maryland; Marilyn Huestis, National Institute on Drug
Abuse; Arthur Strauss, M.D., Long Beach Memorial Medical Center.

The National Institute on Drug Abuse and the National Center for
Research Resources funded the work.